Darren Criss dropped by TV's Conan on August 1, but the usually upbeat Glee star was understandably somber during his first appearance on O’Brien’s show. Criss spoke out about his late co-star Cory Monteith, remembering his great sense of humor and his love for his friends. “I’m just so happy that a guy like him got to touch as many lives as he did while we were all lucky enough to have him,” he told O’Brien. Watch Criss' touching tribute to Monteith, then see the emotional new season of Glee beginning September 26 on FOX.